import React, { useState, useEffect, useRef } from "react";
import { Lock, Coffee, Users, Mail, PanelRight, X } from "lucide-react";
import { toast } from "sonner";
import { Button } from "@/components/ui/button";
import { Switch } from "@/components/ui/switch";

interface ScheduleItem {
  time: string;
  activity: string;
  type: "focused" | "collaborative" | "rest" | "light";
  icon: React.ReactNode;
}

export default function GlobalWorkNotifications() {
  const [currentTime, setCurrentTime] = useState<Date>(new Date());
  const [lastNotifiedIndex, setLastNotifiedIndex] = useState<number>(-1);
  const [showNotificationModal, setShowNotificationModal] = useState<boolean>(false);
  const [notificationsEnabled, setNotificationsEnabled] = useState<boolean>(() => {
    if (typeof window !== 'undefined') {
      const saved = localStorage.getItem('globalWorkNotificationsEnabled');
      return saved !== null ? saved === 'true' : true;
    }
    return true;
  });
  const [currentNotification, setCurrentNotification] = useState<{
    title: string;
    description: string;
    type: "focused" | "collaborative" | "rest" | "light";
  } | null>(null);
  
  const notificationAudioRef = useRef<HTMLAudioElement | null>(null);

  // Initialize audio element
  useEffect(() => {
    const audio = new Audio('/notification.mp3');
    audio.preload = 'auto';
    audio.volume = 1.0; // Full volume
    notificationAudioRef.current = audio;
    
    return () => {
      if (notificationAudioRef.current) {
        notificationAudioRef.current.pause();
        notificationAudioRef.current = null;
      }
    };
  }, []);

  // Save notification preferences
  useEffect(() => {
    localStorage.setItem('globalWorkNotificationsEnabled', notificationsEnabled.toString());
  }, [notificationsEnabled]);

  // Update current time every minute
  useEffect(() => {
    const timer = setInterval(() => {
      setCurrentTime(new Date());
    }, 60000);
    return () => clearInterval(timer);
  }, []);

  // Daily schedule data
  const scheduleItems: ScheduleItem[] = [
    { time: "9:30 AM – 10:30 AM", activity: "Team Collaboration / Planning", type: "light", icon: <Users className="h-4 w-4" /> },
    { time: "10:30 AM – 11:30 AM", activity: "Deep Work Session 1", type: "focused", icon: <Lock className="h-4 w-4" /> },
    { time: "11:30 AM – 12:00 PM", activity: "Team Discussion / Quick Sync", type: "collaborative", icon: <Users className="h-4 w-4" /> },
    { time: "12:00 PM – 1:00 PM", activity: "Deep Work Session 2", type: "focused", icon: <Lock className="h-4 w-4" /> },
    { time: "1:00 PM – 1:45 PM", activity: "Lunch Break", type: "rest", icon: <Coffee className="h-4 w-4" /> },
    { time: "1:45 PM – 2:30 PM", activity: "Team Collaboration / Emails", type: "light", icon: <Mail className="h-4 w-4" /> },
    { time: "2:30 PM – 3:30 PM", activity: "Deep Work Session 3", type: "focused", icon: <Lock className="h-4 w-4" /> },
    { time: "3:30 PM – 4:00 PM", activity: "Team Discussion / Admin Tasks", type: "collaborative", icon: <PanelRight className="h-4 w-4" /> },
    { time: "4:00 PM – 4:15 PM", activity: "Tea Break", type: "rest", icon: <Coffee className="h-4 w-4" /> },
    { time: "4:15 PM – 4:30 PM", activity: "Flex / Light Catch-Up", type: "light", icon: <Users className="h-4 w-4" /> },
    { time: "4:30 PM – 5:30 PM", activity: "Deep Work Session 4", type: "focused", icon: <Lock className="h-4 w-4" /> },
    { time: "5:30 PM – 6:30 PM", activity: "Team Support / Wrap-Up", type: "light", icon: <Users className="h-4 w-4" /> },
  ];

  const playNotificationSound = () => {
    if (notificationAudioRef.current && notificationsEnabled) {
      try {
        notificationAudioRef.current.currentTime = 0;
        notificationAudioRef.current.play().catch(err => {
          console.log("Could not play notification sound:", err);
        });
      } catch (error) {
        console.error("Error playing notification sound:", error);
      }
    }
  };

  const showNotification = (item: ScheduleItem) => {
    if (!notificationsEnabled) return;
    
    playNotificationSound();
    
    const title = `Time for ${item.activity}`;
    const description = `${item.time} - ${
      item.type === "focused" ? "Focus on deep work" : 
      item.type === "collaborative" ? "Connect with your team" : 
      item.type === "rest" ? "Take a break to recharge" : 
      "Handle lighter tasks"
    }`;
    
    toast.info(title, { description });
    
    setCurrentNotification({ title, description, type: item.type });
    setShowNotificationModal(true);
    document.body.classList.add('overflow-hidden');
  };

  // Check current activity and show notifications only when time changes
  useEffect(() => {
    const now = currentTime;
    const hour = now.getHours();
    const minute = now.getMinutes();
    const currentTimeInMinutes = hour * 60 + minute;
    
    const index = scheduleItems.findIndex((item) => {
      const [startTime, endTime] = item.time.split(" – ");
      const [startHour, startMinutePart] = startTime.split(":");
      const startMinute = parseInt(startMinutePart);
      const startHourNum = parseInt(startHour) + (startTime.includes("PM") && parseInt(startHour) !== 12 ? 12 : 0);
      const startTimeInMinutes = startHourNum * 60 + startMinute;
      
      const [endHour, endMinutePart] = endTime.split(":");
      const endMinute = parseInt(endMinutePart);
      const endHourNum = parseInt(endHour) + (endTime.includes("PM") && parseInt(endHour) !== 12 ? 12 : 0);
      const endTimeInMinutes = endHourNum * 60 + endMinute;
      
      return currentTimeInMinutes >= startTimeInMinutes && currentTimeInMinutes < endTimeInMinutes;
    });
    
    // Only show notification if this is not the initial load and the activity has changed
    const isInitialLoad = lastNotifiedIndex === -1;
    
    if (index !== -1) {
      if (!isInitialLoad && index !== lastNotifiedIndex && notificationsEnabled) {
        console.log('Time-based notification triggered for:', scheduleItems[index].activity);
        showNotification(scheduleItems[index]);
      }
      setLastNotifiedIndex(index);
    } else if (isInitialLoad) {
      // If no current activity on initial load, set lastNotifiedIndex to avoid future false triggers
      setLastNotifiedIndex(-2);
    }
  }, [currentTime, scheduleItems, notificationsEnabled]);

  const getModalStyles = (type: "focused" | "collaborative" | "rest" | "light") => {
    switch (type) {
      case "focused": return "bg-purple-50 border-purple-200 text-purple-800";
      case "collaborative": return "bg-blue-50 border-blue-200 text-blue-800";
      case "rest": return "bg-red-50 border-red-200 text-red-800";
      case "light": return "bg-green-50 border-green-200 text-green-800";
      default: return "";
    }
  };

  const getModalIcon = (type: "focused" | "collaborative" | "rest" | "light") => {
    switch (type) {
      case "focused": return <Lock className="h-12 w-12 text-purple-600" />;
      case "collaborative": return <Users className="h-12 w-12 text-blue-600" />;
      case "rest": return <Coffee className="h-12 w-12 text-red-600" />;
      case "light": return <Mail className="h-12 w-12 text-green-600" />;
      default: return null;
    }
  };
  
  const closeModal = () => {
    setShowNotificationModal(false);
    document.body.classList.remove('overflow-hidden');
  };

  useEffect(() => {
    const handleEscapeKey = (event: KeyboardEvent) => {
      if (event.key === 'Escape' && showNotificationModal) {
        closeModal();
      }
    };
    document.addEventListener('keydown', handleEscapeKey);
    return () => document.removeEventListener('keydown', handleEscapeKey);
  }, [showNotificationModal]);

  return (
    <>
      {showNotificationModal && currentNotification && (
        <div className="fixed inset-0 z-50 flex items-center justify-center">
          <div className="absolute inset-0 bg-black bg-opacity-50 backdrop-blur-sm" onClick={closeModal} />
          
          <div className={`relative mx-4 w-full max-w-md rounded-lg border shadow-lg transform transition-all ${getModalStyles(currentNotification.type)}`}>
            <button onClick={closeModal} className="absolute right-4 top-4 rounded-full p-1 text-gray-500 hover:bg-gray-100">
              <X className="h-5 w-5" />
            </button>
            
            <div className="p-6">
              <div className="flex items-start gap-4">
                <div className="p-3 rounded-full bg-white shadow-md">
                  {getModalIcon(currentNotification.type)}
                </div>
                <div className="flex-1 pt-2">
                  <h2 className="text-xl font-bold">{currentNotification.title}</h2>
                  <p className="text-base mt-1 opacity-90">{currentNotification.description}</p>
                </div>
              </div>
              
              <div className="mt-6 p-4 rounded-md bg-white bg-opacity-50">
                {currentNotification.type === "focused" ? (
                  <p className="text-sm">🧠 Time to focus! Close distractions, silence notifications, and dedicate this time to deep, meaningful work.</p>
                ) : currentNotification.type === "collaborative" ? (
                  <p className="text-sm">👥 Connect with your team! This is a good time for meetings, discussions, and collaborative problem-solving.</p>
                ) : currentNotification.type === "rest" ? (
                  <p className="text-sm">🔋 Take a break! Step away from your desk, stretch, or grab a refreshment to recharge your energy.</p>
                ) : (
                  <p className="text-sm">📋 Handle lighter tasks! This is a good time for emails, planning, and administrative tasks.</p>
                )}
              </div>
              
              <div className="mt-6">
                <div className="flex items-center gap-2 mb-4">
                  <Switch 
                    id="global-notification-toggle"
                    checked={notificationsEnabled} 
                    onCheckedChange={setNotificationsEnabled}
                  />
                  <label htmlFor="global-notification-toggle" className="text-sm cursor-pointer">
                    {notificationsEnabled ? "Notifications On" : "Notifications Off"}
                  </label>
                </div>
                
                <Button 
                  onClick={closeModal}
                  className={`font-semibold w-full ${
                    currentNotification.type === "focused" ? "bg-purple-600 hover:bg-purple-700" : 
                    currentNotification.type === "collaborative" ? "bg-blue-600 hover:bg-blue-700" : 
                    currentNotification.type === "rest" ? "bg-red-600 hover:bg-red-700" : 
                    "bg-green-600 hover:bg-green-700"
                  } text-white`}
                >
                  Acknowledge
                </Button>
              </div>
            </div>
          </div>
        </div>
      )}
    </>
  );
}